As Cabinet minister Chris Huhne runs off with his bisexual mistress, Robert
Mendick reveals why it is a very Liberal affair

It is a very liberal love affair. Chris Huhne, the Energy Secretary, leaves his wife of 26 years for a woman not only 13 years younger but also married, albeit to another woman.

Carina Trimingham is not – if there is such a thing – an obvious politician's mistress and certainly not a stereotypical "other woman". As a bisexual with cropped hair and an alleged penchant for Dr Martens boots (a claim which Ms Trimingham is said to deny), she finds herself unhappily at the messy centre of scandal.

Her relationship with Mr Huhne, 55, who declared in a terse statement last week that he was separating from Vicky Pryce, has caused quite a stir. For a start, Ms Pryce, 57, and mother of his three children, is hugely popular in City and government circles, where she works as a high-powered economist. Mr Huhne has been accused of gross hypocrisy, having only last month boasted in election material of his strong marriage and even used photographs from the family album to prove it. Meanwhile, his relationship with Ms Trimingham, 44, has left some onlookers frankly baffled.

One senior Liberal democrat source says: "Why would he leave Vicky for her? His wife may be a bit older but she is a very attractive woman." Others have been altogether harsher. Rod Liddle, the Spectator columnist, writing on his internet blog, admitted his confusion: "I'm not quite sure where I stand on the subject of Chris Huhne and his new, weird-looking quasi-lesbo missus, Carina Trimingham."

The comments have stung Ms Trimingham, who is furious that her private life – including a short-lived previous marriage to a man as well as her civil partnership – has been raked over. She is now considering suing tabloid newspapers for breach of her privacy, The Sunday Telegraph has been told. She has employed the same legal team that represents Vanessa Perroncel, who has been accused of having an affair – which she denies – with the former England captain John Terry, and is also threatening to take legal action.

A source close to Ms Trimingham said: "She is not everybody's idea of a MP's wife, but that is no reason to punish her. She has been depicted as a cartoon lesbian and that is so crass, so crude. Carina is not a public figure, she is not an MP. Just because she is in a relationship with somebody who is himself a public figure does not mean it is OK to talk about what she wears, where she works or her sexual orientation."

There was nothing, moreover, unusual about Mr Huhne falling for a woman who previously lived with another woman. "Carina is clever, funny and interesting," said the source. "Why are we persecuting a woman who has the audacity not to be a bikini babe? It is so old-fashioned."

Mr Huhne refuses to discuss the new love in his life, whom he first employed on his Liberal Democrat leadership campaign in 2007 and which he narrowly lost to Nick Clegg. It has been reported that their romance blossomed in early 2008.

Certainly, while their burgeoning relationship was kept out of the public domain, those who know the Huhnes suggest the marriage was already falling apart. "It was no surprise to me," said one City source, "because we all knew for a long time that he and Vicky were estranged. They have been leading separate lives."

Ms Pryce, described by the source, as "very nice, very bright" is herself a high-flier, a senior civil servant who works for Vince Cable, the Business Secretary. It emerged last week – in a move said to be unconnected with her husband's affair – that Ms Pryce is moving to the private sector to take up a job with a US finance consultancy firm.

Mr Huhne's infidelity, revealed by a Sunday tabloid, has taken some people by surprise. "This is fairly atypical," one former acquaintance remarked with some understatement.

Mr Huhne has a reputation for seriousness that borders on pomposity. He is, in one sense, the Liberal Democrats' Gordon Brown to Nick Clegg's Tony Blair, and is more Left-wing than his party leader. There is even talk that after the leadership election in 2007, the two men agreed that some 1,000 postal ballots that arrived after the deadline because of Christmas post hold-ups should not be counted. It is claimed that most of those votes were for Mr Huhne, who ran a stronger campaign. He agreed not to contest the decision and happily anointed Mr Clegg as leader.

Mr Huhne, may be Left-wing but his roots are positively Tory. His father, Peter Paul-Huhne (the double-barrelled surname was dropped by the aspiring politician during his days at Oxford) was an affluent businessman in west London.

Mr Huhne went to Westminster School, the Sorbonne and then Oxford, where he is remembered for driving his own taxi cab. He became a financial journalist working for a time at the Independent, where colleagues recall him arriving to work in an expensive car with the personalised number plate H11HNE emblazoned upon it. The plate did not impress staff facing redundancies at the time.

One former colleague said: "He does have a lack of self-awareness. He is a genuinely nice bloke but he doesn't quite see himself as others see him and that is part of his problem. That is why he comes across as pompous."

He quit journalism for a more lucrative career in the City, making a small fortune while also serving as an MEP. During that period in the 1990s, he began building up a property portfolio that led to him being nicknamed "Nine Homes Huhne".

As well as the family house in south London and the constituency home in Hampshire, he also rents out five houses in Oxford and London and part-owns another in France, while Ms Pryce, who is Greek – she took her surname from her first marriage – has a home in Greece. Lawyers suggest Ms Pryce will be entitled to half his fortune on divorce.

Last week's headlines must all make uncomfortable reading for Ms Pryce. She was at her husband's side during the election count in Eastleigh in May, but so too was Ms Trimingham, the three of them caught on camera entering the counting hall.

Ms Trimingham knows a bit about public relations. She was once a journalist on the gossip column at the London Evening Standard, then a political reporter for Sky News in London, before working on publicity campaigns for the Liberal Democrats, Amnesty International and latterly the Electoral Reform Society.

She “married” Julie Bennett, a 56-year-old psychotherapist, at a civil partnership ceremony in June 2007. Ms Bennett is now said to be devastated by their split.

Through it all, Mr Huhne – unlike David Laws who fiddled his expenses to keep secret his long-term relationship with another man – will keep his job. After all, the political career of Paddy Ashdown, who was renamed “Paddy Pantsdown” for his fling with his secretary, remained intact. Not only did Lord Ashdown’s marriage survive, the Lib Dem vote went up at the next election.

Other scandal-hit Lib Dems have fared less well. Mark Oaten’s political career on the party’s front bench was wrecked by the revelation he had a relationship with a 23-year-old male prostitute. Simon Hughes’s leadership bid was derailed by his admission, after many denials, that he was actually bisexual, while Lembit Opik lost his seat at the last election, in part due to his affair with a Romanian pop singer Gabriela Irimia, better known as one half of the Cheeky Girls.

It prompted Mr Opik to muse last week on the subject of his party’s sexual proclivities. “Are Lib Dems particularly prone to dangerous liaisons? Does the party attract politicians with the highest libido?” he mused. His conclusion was that, when it came to sex, his party was no more liberal than any other. The wider public may disagree.